Fuse combination unit and operating rocker with monitoring display

ABSTRACT

The invention relates to a fused switch unit ( 1 ) with a housing ( 2 ) and switching rocker ( 30 ), which is mounted in the housing ( 2 ) of the fused switch unit ( 1 ) such that it can pivot to and fro between a switched-on positon and a switched-off position. The fused switch unit ( 1 ) has apparatuses ( 70, 71, 72, 73 ) for a monitoring circuit and an indication ( 35 ) for monitoring the serviceability of a fuse link ( 20 ), with the indication ( 35 ) being arranged in the switching rocker ( 30 ). The indication ( 35 ) is preferably an optical indication.

This application is an application filed under 35 U.S.C. Sec. 371 as anational stage of international application PCT/EP00/06944, which wasfiled Jul. 20, 2000.

TECHNICAL FIELD

The invention relates to a switching rocker for a fused switch unit.

BACKGROUND OF THE INVENTION

Fused switch units such as these, as well as switching rockers used inthem, in whose fuse plugs fuse links can be inserted, are used in a widerange of embodiments in both private and commercial buildings, inparticular in buildings in which machines are electrically operated. Itis also possible to use such fused switch units and components such asthe switching rocker directly on or in machine elements or housings, forelectrical protection of electrically operated machines.

A fused switch unit having a switching rocker of this generic type isknown, for example, from DE 34 06 815 C2. Fused switch units such asthese are used to interrupt the circuit of, and hence the electricalsupply to, machines and appliances automatically when the currentintensity or the power in the circuit exceeds a specific, fixed value.In order to match these values to the circumstances, in particular tothe electrical machines and appliances as well as external requirements,for example safety requirements, fuse links which have differentcharacteristic values can be inserted into the fused switch units, orinto the fuse plug.

The purpose of these fused switch units is to reliably manuallyinterrupt the circuit, in particular when it is necessary to carry outrepairs to the electrical appliances and machines. To do this, theswitching rocker which contains the fuse plug together with thecorresponding fuse link, and which is mounted in a housing of the fusedswitch unit such that it can pivot between a switched-on position and aswitched-off position, is moved to its switched-off position.

Since the fuse links which are used in a fused switch unit are generallyfuses of the type that blow by melting, which may be blown defectivelyor by an excessively high load, it is advantageous to monitor theserviceability of the fuse link by means of a monitoring apparatus. Themonitoring of the serviceability of the fuse link should be understoodas meaning both the monitoring of any defects which may be present inthe fuse link itself and monitoring for any defect in the contact withthe fuse link in a main circuit of the fused switch unit.

A monitoring circuit for this purpose is known, which bridges the inputand the output of the fused switch unit, in parallel with the maincircuit passing through the fuse link, via a very high-impedanceconnection. A lamp is normally integrated as the monitoring indicationin the monitoring circuit.

A significant current flows through the very high-impedance monitoringcircuit only when the low-impedance connection in the main circuit isinterrupted, for example by the blowing of the fuse link. Othermonitoring systems are also possible, but these are all based on aninterruption in the main circuit causing visible changes to occur in themonitoring circuit, which are indicated by means of a monitoringindication. One problem in this context is the position of themonitoring indication.

SUMMARY OF THE INVENTION

Accordingly, one object of the invention is to provide a low-cost fusedswitch unit having a long-life monitoring indication, which is arrangedsuch that a simple structural design, in particular a compact design ofthe fused switch unit, is possible, with the monitoring indication beingintended to supply the operator with information which cannot bemisunderstood.

The object is achieved by a switching rocker for a fused switch unit asclaimed herein, and by a fused switch unit as claimed herein.

According to the invention, the arrangement of the indication in theswitching rocker results in the indication being integrated very well inthe structural design of the fused switch unit, without requiring anyadditional space. The indication can be integrated in the switchingrocker, so that it is protected from the outside and damage is avoided.

Furthermore, the switching rocker is a part which is subject toconsiderably less wear than the fuse plug. The life to be expected forthe monitoring indication is thus noticeably increased in comparison toaccommodation in the fuse plug.

Furthermore, it is feasible to design the fuse link and the fuse plug asa unit, so that different fuse plugs must be made available andinterchanged, depending on the application. Since the monitoringindication is arranged in the switching rocker and not in a part subjectto wear or in a part which can be lost or needs to be replacedregularly, this reduces the overall costs of the fused switch unit.

In comparison to positioning of the monitoring indication in the housingof the fused switch unit, positioning in the switching rocker has, inparticular, the advantage that the fused switch unit can be designed tobe more compact. Installation in the housing would necessitate anincrease in the height of the housing above the area of the switchingrocker, in order to accommodate the monitoring indications in thehousing. If the monitoring indication were arranged at the side in thehousing, this would mean that the fused switch unit would have greaterdimensions in this direction and, furthermore, that disadvantages wouldhave to be accepted with regard to installation of the fused switchunit, since further areas of the fused switch unit need to be visible,that is to say they must not be covered by other elements. Aninstallation of the fused switch unit in which only the minimal areaaround the operating grip of the switching rocker is visible is highlydesirable, on the other hand, in particular for visual reasons, as well.

Furthermore, an arrangement of the monitoring indication in the housingmeans that it is visible not only when the switching rocker is in theswitched-on position, but also when it is in the switched-off position.Since, for safety reasons, the monitoring circuit must be interrupted inthe switched-off position, the monitoring indication in principle doesnot illuminate in the switched-off position, to be precise irrespectiveof the serviceability of the fuse link. It is thus possible, inparticular, for an untrained operator to be irritated by theunilluminated monitoring indication in conjunction with an interruptedcircuit in the switched-off position, possibly unnecessarily replacingserviceable parts, in particular a serviceable fuse link. Such-anirritation to the operator is avoided by the arrangement according tothe invention, when the monitoring indication is not externally visiblein the switched-off position.

In one preferred embodiment, the monitoring indication is arranged in aninner area of the switching rocker.

The monitoring indication is thus protected, so that no damage canoccur, irrespective of whether this is due to external action by theoperator or by contact with other parts of the fused switch unit.

The indication is in this case preferably arranged behind a transparentwindow, or else the switching rocker is produced at least partially fromtransparent material, behind which the monitoring indication can be seenfrom the outside.

It should be stressed that the arrangement in the inner area of theswitching rocker is not intended to adversely affect the capability toreplace the monitoring indication, and, in particular, the windowmentioned above or area elements of the switching rocker, for example,can be opened in order, when necessary, to allow access to themonitoring indication. However, since the monitoring indicationsgenerally have an extremely long life and the time for which they areswitched on and which governs the life is short, such replacementprocesses are necessary only extremely rarely, and the capability toreplace the monitoring indication can thus also be dispensed with, infavor of simpler construction.

It is advantageous to arrange the monitoring indication in the vicinityof an operating grip, in particular on that side of the switching rockerwhich faces the switched-off position. Thus, when the switching rockeris in the switched-on position, the monitoring indication is in acentral, easily visible position, while it is automatically covered byparts of the housing as soon as the switching rocker is in itsswitched-off position. There is thus no need for any additional coveringapparatuses, which results in a simplified structural design both of theswitching rocker and of the fused switch unit.

In one particularly preferred embodiment, the switching rockerfurthermore has apparatuses for the monitoring circuit, in particularcontact elements, and advantageously spring elements, which close themonitoring circuit when the switching rocker is in the switched-onposition, and interrupt it when the switching rocker is in theswitched-off position. This results in an advantageous design, in whichonly simple contact elements need be provided in the housing of thefused switch unit.

The apparatuses for the monitoring circuit are advantageously likewisearranged in the interior of the switching rocker, preferably in the areaof the monitoring indication. The interior is essentially closed, andhas only contact openings, in order that contact can be made with thecontact elements arranged in the housing.

The contact and/or connecting elements which make contact with theapparatuses for the monitoring circuit when the switching rocker is inthe switched-on position are preferably elements of the main circuit.This means that there is no need to provide any additional elements,thus reducing the costs and the susceptibility of the fused switch unitto defects.

However, it is also possible to provide at least one contact apparatus,preferably a spring apparatus, which makes contact with at least onecontact element in the monitoring circuit when the switching rockerassumes its switched-on position.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in more detail in the following textwith reference to the schematic illustration of a fused switch unit anda switching rocker, in which:

FIG. 1 shows a cross-sectional view of one embodiment of a fused switchunit with a switching rocker in the switched-on position, and

FIG. 2 shows the fused switch unit as shown in FIG. 1, with theswitching rocker in the switched-off position.

FIG. 1 shows one embodiment of a fused switch unit 1 with a housing 2and a switching rocker 30 in the switched-on position. A fuse plug 10,which holds a fuse link 20, is inserted into the switching rocker 30.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

When the switching rocker 30 is in the switched-on position, the fuselink 20 is connected by means of contact elements 70, 71, 72, 73 to aninput and an output, so that the main circuit is closed. The fuse link20 is in this case pressed by a spring apparatus 98 against the directcontact elements 70, as well as 71 and 72.

The contact element 70, which is in the form of a spring, in this caseessentially carries out three functions. Contact is made via the contactelement 70 with the electronics arranged in the fused switch unit.Furthermore, the element 70, which is in the form of a spring, holds thefuse link 20 in the desired position relative to the fuse plug 10 and,furthermore, fixes the position of the fuse plug 10 in the switchingrocker 30.

The monitoring circuit likewise uses the contact elements 70, 71 of themain circuit on one side, and closes the monitoring circuit via furthercontact elements 50, 52, 53 and a high-value resistor 51. The contactelements 50 and 52 as well as the resistor 51 are arranged in theinterior 32 of the switching rocker 30.

The contact elements 50, 52 and 53 are likewise spring elements, thusensuring reliable contact.

Furthermore, an optical monitoring indication, a lamp 35 which isindicated only schematically here, is arranged in the interior 32 of theswitching rocker 30. As soon as the main circuit is interrupted, inparticular by the fuse link 20 blowing, a sufficient current flowsthrough the monitoring circuit to illuminate the monitoring indication35. This indicates that there is a defect in the main circuit.

The monitoring indication 35 is positioned behind a transparent window33, so that the operator can see the monitoring light in the switchingrocker 30, which is otherwise composed of material that is nottransparent.

The interior 32 of the switching rocker 30 in which, as described above,both the lamp 35 and a number of apparatuses for the monitoring circuitare arranged, is essentially completely closed, thus preventing damageto the apparatuses. The interior 32 has only two contact openings 56 and57, in order to allow contact between the contact apparatuses 52 and 53,as well as 50 and 70. The contact between the elements 50 and 70 isalways closed as soon as a fuse plug 10 with a fuse link 20 is insertedinto the switching rocker 30. The contact between the contact elements52 and 53 exists only when the switching rocker 30 assumes itsswitched-on position.

FIG. 2 shows the switching rocker 30 in its switched-off position. Itcan be seen that both the main circuit and the monitoring circuit areeach interrupted twice, namely firstly between the contact elements 70and 71 and between the contact element 72 and the fuse link 20, andsecondly at the jointly used contact elements 70 and 71, as well as atthe contact elements 52 and 53.

The sprung contact element 53 engages in a recess 80 in the outer wallof the inner area 32 of the switching rocker 30, and is thus positionedreliably.

The connection between the contact elements 50 and 70 still exists,since the fuse plug 10, together with the fuse link 20, is still in theoperating position in the switching rocker 30.

As can likewise be seen from FIG. 2, the monitoring indication 35 iscovered on the outside both by the operating grip 31 of the switchingrocker 30 and by the housing 2, so that the monitoring indication 35cannot be seen by the observer. The monitoring indication 35 can be seenonly when the switching rocker 30 is in the switched-on position, sinceit is then in a central position within an opening 90 in the housing 2,through which the operating grip of the switching rocker 30 projects.

Both the operating grip 31 on the switching rocker 30 and the grip part11 of the fuse plug 10 have through-openings 95 and 96, which are offsetwith respect to one another when the fuse plug 10 is in a limit positionsuch that it is inserted into the switching rocker 30, and they are thusnot aligned with one another. These through-openings 95, 96 are used fora locking apparatus (not shown) to be passed through.

In order to pass the locking apparatus through, the fuse plug 10 must bewithdrawn from its limit position in the switching rocker 30, so thatthe through-openings 95 and 96 are at least partially aligned. A lockingapparatus which is then pushed through the through-openings 95, 96prevents the fuse plug 10 from being pushed back to its limit position.However, if the fuse plug 10 is not in its limit position, the switchingrocker 30 cannot be pivoted to its switched-on position, since parts ofthe fuse plug 10 abut against parts of the housing 2, and prevent theswitching rocker 30 from being switched to the switched-on position. Theswitching rocker 30 is thus reliably held in its switched-off position,which is of particular importance when it is necessary to carry outrepairs on machines or electrical appliances which are supplied via thefused switch unit 1. This thus reliably prevents accidental switchingon, or switching on caused, for example, by vibration,and hence preventsany hazard to the operator.

List of Reference Symbols

1 Fused switch unit

2 Housing

10 Fuse plug

11 Grip part (fuse plug)

20 Fuse link

30 Switching rocker

31 Operating grip (switching rocker)

32 Inner area (switching rocker)

33 Window

35 Monitoring indication

50 Contact element

51 Resistor

52 Contact element

53 Contact apparatus (housing)

56, 57 Contact opening

70, 71, 72, 73, Contact elements

90 Opening (housing)

95, 96 Through-openings (fuse plug and operating grip)

98 Spring apparatus

What is claimed is:
 1. A switching rocker (30) for a fused switch unit(1), said switching rocker (30) being designed such that a fuse plug(10) for holding a fuse link (20) can be inserted in said switchingrocker (30), said switching rocker being mounted in a housing (2) of afused switch unit (1) such that said switching rocker (30) can pivot toand fro between a switched-off position and a switched-on position,wherein the switching rocker (30) has an indication (35) for monitoringthe serviceability of the fuse link (20).
 2. The switching rocker asclaimed in claim 1, wherein the indication (35) is arranged in an innerarea (32) of the switching rocker (30).
 3. The switching rocker asclaimed in claim 1, wherein said indication (35) is an opticalindication (35) arranged behind a transparent window (33).
 4. Theswitching rocker as claimed in claim 1, wherein the switching rocker(30) is at least partially composed of transparent material, with saidindication (35) is an optical indication (35) arranged behind thetransparent material.
 5. The switching rocker as claimed in claim 1,wherein the indication (35) is arranged in the vicinity of an operatinggrip (31) on the switching rocker (30).
 6. The switching rocker asclaimed in claim 1, wherein the indication (35) is arranged on one sidewhich faces the switched-off position of the switching rocker (30) of agrip part (31) thereof, such that it is covered by parts of the housing(2) when the switching rocker (30) is in the switched-off position, andcan be seen when the switching rocker (30) is in the switched-onposition.
 7. The switching rocker as claimed in claim 1, wherein theswitching rocker (30) has apparatuses (50, 51, 52) for a monitoringcircuit.
 8. The switching rocker as claimed in claim 7, wherein theapparatus (50, 51, 52) for a monitoring circuit has contact elements(50, 52) which close the monitoring circuit when the switching rocker(30) is in the switched-on position, and interrupt it when the switchingrocker (30) is in the switched-off position.
 9. The switching rocker asclaimed in claim 7, wherein the apparatuses (50, 51, 52) for themonitoring circuit are arranged in an inner area (32) of the switchingrocker (30).
 10. The switching rocker as claimed in claim 9, wherein theinner area (32) is essentially intrinsically closed, and with theexception of contact openings (56, 57) for the contact elements (50,52).
 11. A fused switch unit (1) with a housing (2) and a switchingrocker (30) as claimed in claim 1 wherein said switching rocker (30) ismounted in the housing (2) of the fused switch unit (1) such that saidswitching rocker (30) can pivot to and fro between a switched-onposition and a switched-off position, said fused switch unit (1)including apparatuses (50, 51, 52, 53) for a monitoring circuit as wellas an indication (35) for monitoring the serviceability of the fuse link(10), wherein the indication (35) is arranged in the switching rocker(30), with indication (35) being an optical indication.
 12. The fusedswitch unit as claimed in claim 11, wherein contact and/or connectingelements (70, 71) of the housing (2), of the switching rocker (30)and/or of the fuse plug (10) form both elements of a main circuit andelements of the monitoring circuit.
 13. The fused switch unit as claimedin claim 11, wherein the housing (2) further has at least one contactapparatus (53), which makes contact with at least one contact element(52), which is arranged in the switching rocker (30) or in the fuse plug(10), when the switching rocker (30) is in a switched-on positon, sothat the monitoring circuit is closed, and does not make contact withthe at least one contact element (52) when the switching rocker (30) isin a switched-off position, so that the monitoring circuit isinterrupted.